A Dia de los Niños event turned tragic when a 16-year-old girl was killed and a 15-year-old girl was injured after they were thrown from a carnival ride Friday evening at St. Thomas Aquinas Catholic Church in East El Paso, police said.

The girl died at Del Sol Medical Center, police said. The 15-year-old girl was taken to University Medical Center of El Paso with injuries that were not believed to be life-threatening, police said.

The girls were riding "Sizzler," a ride that spins around, authorities said.

There were three girls in the ride and two were ejected shortly before 7 p.m. in the church parking lot at 10970 Bywood Drive, a few blocks east of Lee Treviño Drive, police spokesman Sgt. Enrique Carrillo said.

The third girl was not ejected and wasn't injured, Carrillo said.

"We don't know the cause," he said.

Police closed the carnival for the night, sealing it off with red crime scene tape as investigators worked the scene. It wasn't known whether it would open Saturday.

The accident was under investigation by the police Crimes Against Persons Unit, which investigates deaths.

People at the carnival said it was being held in celebration of Dia de los Niños.

China Arevalo and her family were selling elotes, corn in a cup and other snacks at the carnival when they heard a commotion and were told that someone had fallen off one of the rides.

"There was a girl on the ground and they were doing CPR to revive her," Arevalo said. Three ambulances arrived and the girl was carried to an ambulance.

Arevalo said it appeared that the girl had regained consciousness in the ambulance but there was a large puddle of blood on the ground from an injury to the back of her head,

Parishioner Isabel Estrada, 57, who lives nearby, went to the scene with her grandchildren after they noticed emergency vehicles at the carnival. She said that the parish priest wanted to have the carnival in celebration of Dia de los Niños, a Mexican holiday celebrated on April 30.

"He is a very good priest. He wanted to do something for Dia de los Niños," Estrada said. "Who would have thought something like this would happen?"

In 2014, a boy and a girl, both age 13, were injured after falling 12 feet off a carnival ride named the "Sidewinder" at a St. Anthony Seminary's Annual Bazaar in Central El Paso, according to El Paso Times archives.

A check of sites listing roller coaster accidents found several deaths on “Sizzler” rides in cities including Hope, Ark.; Austin; and Durango, Colo.